Browsing Faculty of Science by Author "Nsinamwa, M."
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Kayombo, B.; Meulenburg, F.; Moganane, B. G.; Dikinya, O.; Aliwa, J. N.; Nsinamwa, M.; Gaboutloeloe, G.; Patrick, C.; Mzuku, M.; Machacha, S. (University of Botswana, http://www.ub.bw, April NaN, 2005)[more][less]
Abstract: A study was carried out during 1998-2001 with the objective of, firstly, assessing the impact of cultivation on soil quality, and secondly, evaluating the effects of human and animal activities on soil erosion and range resources. A Topical Rapid Rural Appraisal (TRRA) based on rapid appraisal approaches, was conducted in three benchmark villages in Bobirwa Sub-district. A diagonistic survey report provided similar information for Kgalagadi District. Three benchmark sites were located in Bobirwa Sub-district and two others in Kgalagadi District. Soils were characterized at benchmark sites and in the laboratory for physiochemical properties. Soil erosion was monitored using embedded nail technique. At all benchmark sites, trends show a deterioration of soil quality, both in terms of nutrient depletion and poor physical properties for cultivated soils in comparison to uncultivated soils. There is visible evidence of environmental degradation of land resources resulting partly from considerable soil trampling and loosening during the dry season by livestock. During the wet season, the loosened soil is washed down elsewhere and/or deposited at watering points. The confounding effects of drought, overgrazing, poor management and ever-increasing utilization of veld products have led to the decline of a considerable number of tree and grass species. URI: http://hdl.handle.net/10311/645 Files in this item: 1
Kayombo_BJT_2005.pdf (3.655Mb) -
Nsinamwa, M.; Sebego, R.J. (Botswana College of Agriculture, http://www.bca.bw/Research/bojaasBca/InstructionToAuthors.htm, NaN, 2007)[more][less]
Abstract: Grasses and forbs in Southern Africa have been understudied in terms of species richness and factor that affect diversity patterns. To gain a better understanding of factors affecting patterns of herbaceous plant species seedbank around water points, six boreholes ( three in each land zone) were randomly selected for sampling. Top soil layers of 20cm depth were sampled from six boreholes at distances of 50, 100, 200, 400, 800, 1500, and 3000m ( the Piosphere approach) in fenced and unfenced plots to determine the density and composition of the seedbank. The samples were allowed to germinate in the growth tray (10 x 15 x 8cm³) under controlled conditions (temperature, moisture) in a green house followed by daily counting of seedlings. Herbaceous plant species diversity was analyzed by using Simpson's diversity index. Analysis of varience on herbaceous species diversity was determined using the SAS software. Herbaceous plant community clustering was determined by using TWINSPAN, a FORTRAN programme. Significant (p=0.0001) germination variants were observed along the distance from livestock watering points. Most grass seedlings recorded germinated from soil samples obtained from from fenced plots, while less than 40% of the forb seedlings were. Most of the forbs species were recorded within 400m from the water points and that soils closer to water points also contained grass seeds despite the level of degradation and /or trampling. URI: http://hdl.handle.net/10311/313 Files in this item: 1
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